UV glue for holographic IMR membrane and holographic membrane prepared from UV glue

Abstract

The invention discloses UV glue for a holographic IMR diaphragm and the holographic diaphragm prepared from the UV glue. The UV glue is prepared from the following raw materials: vinyl silane, polyester acrylate, aliphatic polyurethane acrylate, trifunctional sulfydryl modified acrylate, a bifunctional active monomer, a trifunctional active monomer and a photoinitiator. The bifunctional active monomer comprises one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate and triethylene glycol diacrylate. And the trifunctional active monomer is trimethylolpropane triacrylate or pentaerythritol triacrylate. A silicon-oxygen bond in the added vinyl silane has hydrophilicity and can be subjected to a hydrolysis reaction with water molecules in air in a high-temperature and high-humidity environment to generate a Si-OH intermediate, and then the Si-OH intermediate and the silicon-oxygen bond are condensed to form a Si-O-Si bond, so that the compactness of a cross-linked network is further enhanced; and the light-cured coating has excellent water resistance and temperature resistance.

Description

Technical Field

[0001] The invention relates to the technical field of UV glue, and in particular to UV glue for a holographic IMR film and a holographic film prepared by using the UV glue. Background Art

[0002] UV molding technology is a surface treatment technology that uses ultraviolet light curing technology to achieve 3D graphic surface processing. Through this technology, various exquisite patterns and texts can be formed on the surface of the product, improving the appearance quality and market competitiveness of the product. Compared with the traditional hot molding method, UV curing technology can rely on the high energy of ultraviolet light to quickly cross-link the resin molecules in a very short time to form a stable cured layer. No heating is required during the curing process and no harmful gases are released, which meets environmental protection requirements. It has shown significant advantages in curing efficiency and speed, curing quality and accuracy, environmental protection and energy saving, convenience and flexibility of operation, etc., and is currently widely used in surface decoration in the packaging industry, electronics industry, automotive industry, etc.

[0003] In-mold decoration technology (IMR) is to use a high-precision film feeding device to feed a film with a holographic effect into a special molding mold for precise positioning, and then closely fit the film and the plastic film cavity together for injection molding, and then separate the ink layer with a holographic pattern from the PET film, and leave the ink layer on the surface of the plastic product to obtain a plastic part with a decorative pattern. The present invention provides a UV glue for holographic molding and a holographic IMR film prepared using the same.

[0004] like Figure 1 The figure shows the structure of the holographic IMR film, which includes, from bottom to top, a base film layer, a release layer, a holographic layer, an aluminum-plated layer, an ink layer, and an adhesive layer.

[0005] The plastic parts with decorative patterns obtained after injection molding are as follows Figure 2 As shown, the base film layer is peeled off, the release layer is peeled off along with the base film, and the holographic effect is transferred to the surface of the plastic part through the adhesive layer.

[0006] UV glue is needed to transfer the photolithography pattern on the mold to the PET film using UV molding technology. When the UV glue is not cured, if the ambient humidity is 70% RH or higher, the high humidity air will be condensed or adsorbed on the surface of the bonded material, thereby acting as an obstacle between the UV glue and the substrate, reducing the adhesion of the UV glue to the material. And for the cured UV glue, long-term exposure to high temperature and high humidity environment may also cause hydrolysis of the glue layer structure, affect the performance of the UV resin, and reduce the adhesion and cohesion of the UV glue.

[0007] For decorative plastic parts formed by injection molding with holographic IMR films, the UV holographic layer is on the outermost surface of the plastic parts, which not only has a decorative effect, but also a protective effect. In addition, this type of decorative plastic parts are currently widely used in different fields such as home appliance panels, automotive interior and exterior decoration, 3C products, etc. Its clear functional usage requirements and complex and changeable application scenarios require decorative plastic parts to withstand rigorous external resistance tests. This requires that UV glue can show excellent adhesion under different temperature and humidity environments, and the cured coating must be able to resist external temperature and water and oxygen erosion.

[0008] Conventional UV glues generally add antioxidants and stabilizers to enhance their resistance to water and oxygen corrosion, but the amount of additives added is difficult to control. A small amount is difficult to achieve the required resistance requirements, while a large amount can easily affect the appearance and chemical properties of the glue.

[0009] Based on this, the present invention proposes a UV glue suitable for a holographic IMR film and a holographic film prepared using the UV glue. Summary of the invention

[0010] Based on the above description, the present invention provides a UV glue for holographic IMR film, a preparation method of the UV glue, a holographic IMR film made with the UV glue, and a preparation method of the film to solve the problem of UV glue resistance. The UV glue prepared by the present invention is used as a material for UV holographic molding, which can show good resistance to external erosion.

[0011] The technical solution of the present invention to solve the above technical problems is as follows:

[0012] A UV glue for a holographic IMR film comprises the following raw materials by weight: 3-10 parts of vinyl silane, 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, 10-20 parts of trifunctional mercapto-modified acrylate, 25-40 parts of bifunctional active monomer, 5-10 parts of trifunctional active monomer and 3-6 parts of photoinitiator.

[0013] Based on the above technical solution, the present invention can also be improved as follows.

[0014] Furthermore, the bifunctional reactive monomer includes one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate, and triethylene glycol diacrylate.

[0015] Furthermore, the trifunctional reactive monomer is one of trimethylolpropane triacrylate or pentaerythritol triacrylate.

[0016] Furthermore, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone.

[0017] Furthermore, the vinyl silane is one of vinyl triethoxy silane or vinyl trimethoxy silane.

[0018] The method for preparing a UV glue for a holographic IMR film described in any of the above items comprises the following steps: weighing 30-50 parts of an active monomer, adding 3-6 parts of a photoinitiator, stirring evenly, then sequentially adding 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, and 10-20 parts of trifunctional mercapto-modified acrylate, stirring until completely dispersed, and finally adding 3-10 parts of vinyl silane, stirring and dispersing evenly, and standing in a dark place to obtain a UV glue;

[0019] The reactive monomers include bifunctional reactive monomers and trifunctional reactive monomers.

[0020] The present invention also provides a holographic IMR film, which comprises, from bottom to top, a base film layer, a release layer, a holographic layer, a plating layer, an ink layer, and a glue layer. The holographic layer is made by UV embossing using the UV glue prepared according to claim 6, and has a thickness of 5-15 μm.

[0021] Furthermore, in the above-mentioned holographic IMR film, the base film layer is polyethylene terephthalate with a thickness of 35-50 μm.

[0022] Furthermore, in the above-mentioned holographic IMR film, the release layer is a silicone coating, which is peeled off together with the base film layer after injection molding, and the coating is an aluminum coating layer or a transparent medium layer.

[0023] The method for preparing a holographic IMR film described in any of the above items comprises performing UV molding on a base film layer coated with a release layer, transferring the holographic pattern on the nickel plate to the surface of the release layer by UV glue, and then completing the coating of the plating layer, the ink layer and the glue layer in sequence to obtain the IMR holographic film.

[0024] Compared with the prior art, the technical solution of the present invention has the following beneficial technical effects:

[0025] In the embodiment of the present invention, a UV glue for a holographic IMR film and a holographic film prepared by using the same are provided. The advantage of the UV glue is that it has excellent resistance to high temperature, high humidity and water boiling, and can perfectly present a holographic effect through UV molding. After the prepared IMR holographic film is coated on the surface of the plastic part by injection molding, the base film and the release layer are peeled off, and the UV holographic layer is on the outermost surface of the plastic part, which can provide the product with good scratch resistance, wear resistance, weather resistance, and water and oxygen erosion resistance. Even if it is placed in a high-temperature humid test box with a temperature of 70°C ± 2°C and a humidity of 95 ± 1% for 120 hours and boiled in water at 85°C for 2 hours, the tested samples still have no abnormal appearance and the adhesion can still reach level 0.

[0026] The reasons are as follows: 1. The trifunctional active monomer added to the UV glue formula in the embodiment of the present invention makes the UV glue cure faster and has a better dilution effect, and can effectively adjust the viscosity of the UV glue to suit the process requirements. In addition, its multifunctional characteristics can also give the photocurable coating high hardness and high wear resistance.

[0027] 2. The trifunctional mercapto-modified acrylate added to the UV glue formula of the embodiment of the present invention has three reactive double bonds or mercapto groups, which not only improves the curing speed of the UV glue, but also helps to form a denser cross-linking network, thereby enhancing the hardness, mechanical properties and chemical resistance of the photocurable coating. In addition, during the photocuring process, the mercapto compound can overcome the oxygen inhibition problem in the free radical polymerization process and improve the curing efficiency.

[0028] 3. The vinyl silane added to the UV glue formula of the embodiment of the present invention contains active silane groups, which can construct a three-dimensional network structure through Si-O-Si bonds in the glue formula. This strong silicon-oxygen bond network can significantly improve the mechanical properties of the UV light-cured coating. In addition, its molecules contain carbon-carbon double bonds that can participate in free radical reactions and can react with organic molecules in the UV glue. After light curing, the molecules containing silane groups are grafted onto acrylates, which can better enhance the cohesion and bonding strength of the UV glue without adversely affecting the light-cured holographic effect.

[0029] 4. The siloxane bonds in the vinyl silane added to the UV glue formula of the embodiment of the present invention are hydrophilic. Under high temperature and high humidity conditions, they can undergo hydrolysis reactions with water molecules in the air to generate Si-OH intermediates. Subsequently, the Si-OH intermediates and siloxane bonds undergo condensation to form Si-O-Si bonds, further enhancing the compactness of the cross-linked network, so that the photocured coating has excellent water resistance, temperature resistance, and chemical resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the structure of a holographic IMR film provided by an embodiment of the present invention;

[0031] Figure 2 It is a schematic diagram of the structure of a plastic part with holographic decorative effect;

[0032] Figure 3 A process flow chart of the UV molding process for preparing a holographic IMR film provided in an embodiment of the present invention.

[0033] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0034] 101. base film layer, 102. release layer, 103. holographic layer, 104. coating layer, 105. ink layer, 106. adhesive layer, 201. plastic part. DETAILED DESCRIPTION

[0035] In order to facilitate understanding of the present application, the present application will be described more comprehensively below. The present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0037] The technical solution provided by the present invention is as follows:

[0038] Provided is a UV glue for a holographic IMR film, which comprises the following raw materials in parts by weight: 3-10 parts of vinyl silane, 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, 10-20 parts of trifunctional mercapto-modified acrylate, 25-40 parts of difunctional active monomers, 5-10 parts of trifunctional active monomers, and 3-6 parts of photoinitiator.

[0039] Furthermore, the bifunctional reactive monomer includes one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate, and triethylene glycol diacrylate.

[0040] Furthermore, the trifunctional reactive monomer is one of trimethylolpropane triacrylate or pentaerythritol triacrylate.

[0041] Furthermore, the photoinitiator is 1-hydroxycyclohexyl phenyl ketone (BASF IRG 184).

[0042] Furthermore, the vinyl silane is one of vinyl triethoxy silane and vinyl trimethoxy silane.

[0043] The preparation method of UV glue for holographic IMR film described in the present invention is as follows:

[0044] Weigh 30-50 parts of active monomer, add 3-6 parts of photoinitiator, stir evenly, then add 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, 10-20 parts of trifunctional mercapto-modified acrylate, stir until completely dispersed, and finally add 3-10 parts of vinyl silane and stir and disperse evenly. After standing for 12 hours away from light, UV glue is obtained.

[0045] The present invention also prepares a holographic IMR film, which comprises, from bottom to top, a base film layer 101, a release layer 102, a holographic layer 103, a coating layer 104, an ink layer 105, and a glue layer 106. The holographic layer 103 is made by UV embossing using the above-mentioned UV glue, and has a thickness of 5-15 μm. The base film layer 101 is polyethylene terephthalate (PET) with a thickness of 35-50 μm. The release layer 102 is a silicone coating, which is peeled off together with the base film layer 101 after injection molding. The coating layer 104 is an aluminum coating layer or a transparent medium layer. The following embodiments are mainly described by taking the aluminum coating layer as an example.

[0046] The preparation method of IMR holographic film is as follows:

[0047] UV molding is performed on the base film layer coated with the release layer 102 (as follows Figure 3 As shown in FIG. 1 , which is a UV molding process), the holographic pattern on the nickel plate is transferred to the surface of the release layer 102 through UV glue. After that, the aluminum plating layer, the ink layer 105 and the glue layer 106 are coated in sequence to obtain the IMR holographic film.

[0048] Afterwards, the prepared IMR film is used for injection molding, and after the base film and the release are peeled off, an IMR plastic part 201 with a holographic texture effect on the surface is obtained. The outermost surface of this type of plastic part 201 is a UV holographic layer 103, which can not only provide the product with a rich variety of holographic texture effects to enhance its aesthetics, but also has good scratch resistance, wear resistance, and weather resistance, and can protect downstream products, resist external erosion, prevent the internal coating from being damaged, and enhance the service life of the product. Compared with the prior art, the UV glue provided in the present invention has excellent water and oxygen resistance, and the adhesion and cohesion of the UV holographic layer 103 after curing in an extremely high temperature and high humidity environment will not change, and it can still show good adhesion. Moreover, compared with the UV glue modified by adding antioxidants in the traditional technology, the UV glue prepared in the present invention has excellent transparency and fluidity, which can ensure the best holographic effect.

[0049] In the present invention, metal aluminum is used as the coating layer 104 , which can also be replaced by a transparent medium layer. Alternative solutions for the IMR film structure can be a base film layer 101 , a release layer 102 , a holographic layer 103 , a transparent medium layer, an ink layer 105 , and an adhesive layer 106 .

[0050] Material sources: Polyester acrylate is selected from Sartomer CN8010, aliphatic polyurethane acrylate is selected from Sartomer CN9006NS, trifunctional mercapto-modified acrylate is selected from Runao Chemical FSP8630, vinyl triethoxy silane is selected from Sangjing Chemical A-151NT, vinyl trimethoxy silane is selected from Sangjing Chemical A-171, photoinitiator is selected from BASF IRG184, dipropylene glycol diacrylate is selected from Changxing Chemical EM222, tripropylene glycol diacrylate is selected from Changxing Chemical ETERMER223, triethylene glycol diacrylate is selected from Changxing Chemical EM328, trimethylolpropane triacrylate is selected from Changxing Chemical EM231TF, pentaerythritol triacrylate is selected from Changxing Chemical EM235.

[0051] The present invention is further described in detail below in conjunction with embodiments and comparative examples:

[0052] Embodiment 1: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the UV glue.

[0053] Preparation of UV glue: weigh 25 parts of active monomers dipropylene glycol diacrylate, 15 parts of tripropylene glycol diacrylate, 8 parts of trimethylolpropane triacrylate, add 4 parts of photoinitiator BASF IRG 184, stir evenly, then add 15 parts of polyester acrylate, 18 parts of aliphatic polyurethane acrylate, 10 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 5 parts of vinyl triethoxysilane and stir and disperse evenly. After standing for 12 hours away from light, UV glue can be obtained.

[0054] Preparation of IMR holographic film: A 35 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 5 μm. Then, the aluminum plating layer, ink layer 105 and adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0055] Embodiment 2: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the UV glue.

[0056] Preparation of UV glue: weigh 25 parts of active monomers dipropylene glycol diacrylate, 15 parts of triethylene glycol diacrylate, 8 parts of pentaerythritol triacrylate, add 4 parts of photoinitiator BASF IRG 184, stir evenly, then add 15 parts of polyester acrylate, 18 parts of aliphatic polyurethane acrylate, 10 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 5 parts of vinyl trimethoxysilane and stir and disperse evenly. After standing for 12 hours away from light, UV glue can be obtained.

[0057] Preparation of IMR holographic film: A 35 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 5 μm. Then, the aluminum plating layer, ink layer 105 and adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0058] Embodiment 3: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the UV glue.

[0059] Preparation of UV glue: weigh 20 parts of active monomers dipropylene glycol diacrylate, 10 parts of tripropylene glycol diacrylate, 10 parts of triethylene glycol diacrylate, 5 parts of trimethylolpropane triacrylate, add 4 parts of photoinitiator BASF IRG 184, stir evenly, then add 16 parts of polyester acrylate, 16 parts of aliphatic polyurethane acrylate, 10 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 5 parts of vinyl trimethoxysilane and stir and disperse evenly. After standing for 12 hours away from light, UV glue can be obtained.

[0060] Preparation of IMR holographic film: A 50 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 5 μm. Then, the aluminum plating layer, ink layer 105 and adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0061] Embodiment 4: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the UV glue.

[0062] Preparation of UV glue: weigh 20 parts of active monomers dipropylene glycol diacrylate, 12 parts of tripropylene glycol diacrylate, 6 parts of trimethylolpropane triacrylate, add 4 parts of photoinitiator BASF IRG 184, stir evenly, then add 18 parts of polyester acrylate, 21 parts of aliphatic polyurethane acrylate, 12 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 7 parts of vinyl trimethoxysilane and stir and disperse evenly. After standing for 12 hours away from light, UV glue can be obtained.

[0063] Preparation of IMR holographic film: A 50 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 7 μm. Then, an aluminum coating layer, an ink layer 105 and an adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0064] Embodiment 5: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0065] Preparation of UV glue: weigh 16 parts of active monomers dipropylene glycol diacrylate, 10 parts of triethylene glycol diacrylate, 5 parts of pentaerythritol triacrylate, add 4 parts of photoinitiator BASF IRG 184, stir evenly, then add 20 parts of polyester acrylate, 25 parts of aliphatic polyurethane acrylate, 15 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 7 parts of vinyl trimethoxysilane and stir and disperse evenly. After standing for 12 hours away from light, UV glue can be obtained.

[0066] Preparation of IMR holographic film: A 50 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 11 μm. Then, an aluminum coating layer, an ink layer 105 and an adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0067] Embodiment 6: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0068] Preparation of UV glue: weigh 30 parts of active monomer tripropylene glycol diacrylate, 10 parts of pentaerythritol triacrylate, add 6 parts of photoinitiator BASF IRG 184, stir evenly, then add 25 parts of polyester acrylate, 15 parts of aliphatic polyurethane acrylate, 20 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, and finally add 10 parts of vinyl trimethoxysilane and stir and disperse evenly. After standing for 14 hours away from light, UV glue can be obtained.

[0069] Preparation of IMR holographic film: A 38 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 8 μm. Then, an aluminum coating layer, an ink layer 105 and an adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0070] Embodiment 7: This embodiment provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0071] Preparation of UV glue: weigh 25 parts of active monomer triethylene glycol diacrylate, 7 parts of pentaerythritol triacrylate, add 3 parts of photoinitiator BASF IRG 184, stir evenly, then add 22 parts of polyester acrylate, 23 parts of aliphatic polyurethane acrylate, 17 parts of trifunctional mercapto-modified acrylate, stir until completely dispersed, and finally add 3 parts of vinyl triethoxysilane and stir and disperse evenly. After standing for 10 hours away from light, UV glue can be obtained.

[0072] Preparation of IMR holographic film: A 45 μm PET base film is selected, and after release coating, UV molding is performed to obtain a UV holographic layer 103 with a thickness of 13 μm. Then, an aluminum coating layer, an ink layer 105 and an adhesive layer 106 are coated in sequence to obtain an IMR holographic film.

[0073] Comparative Example 1: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0074] The steps are similar to those of Example 1, except that no vinyl triethoxy silane is added when preparing the UV glue. The improvement effect of vinyl triethoxy silane on the UV glue is investigated by comparing the performance of Example 1 with that of Comparative Example 1.

[0075] Comparative Example 2: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0076] The steps are similar to those of Example 2, except that no vinyl trimethoxy silane is added when preparing the UV glue. The improvement effect of vinyl trimethoxy silane on the UV glue is investigated by comparing the performance of Example 2 with that of Comparative Example 2.

[0077] Comparative Example 3: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0078] The steps are similar to those of Example 3, except that trimethylolpropane triacrylate is not added when preparing the UV glue. The improvement effect of the trifunctional reactive monomer on the UV glue is investigated by comparing the performance of Example 3 with that of Comparative Example 3.

[0079] Comparative Example 4: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0080] The steps are similar to those of Example 3, except that no trifunctional mercapto-modified acrylate is added when preparing the UV glue. The improvement effect of trifunctional mercapto-modified acrylate on UV glue is investigated by comparing the performance of Example 3 and Comparative Example 4.

[0081] Comparative Example 5: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0082] The steps are similar to those of Example 3, except that the polyester acrylate is completely replaced by polyether acrylate when preparing the UV glue. By comparing the performance of Example 3 and Comparative Example 5, it is examined whether the use of other types of modified acrylates will affect the performance of the glue.

[0083] Comparative Example 6: This comparative example provides a UV glue for a holographic IMR film and a holographic film prepared using the same.

[0084] The steps are similar to those of Example 3, except that the aliphatic polyurethane acrylate is completely replaced with polyether acrylate when preparing the UV glue. By comparing the performance of Example 3 and Comparative Example 6, it is examined whether the use of other types of modified acrylates will affect the performance of the glue.

[0085] Afterwards, in order to better compare the performance of the UV glue provided in the present invention, various performance tests were conducted on the IMR films prepared by Examples 1-5 and Comparative Examples 1-6, including hardness test, wear resistance test, release peeling performance test, adhesion test, high temperature and humidity resistance test, water boiling resistance test, and UV aging resistance test. The test results are shown in the following table:

[0086]

[0087]

[0088] In the present invention, the UV glue is modified by multifunctional prepolymers such as vinyl silane, multifunctional active monomers and trifunctional mercapto-modified acrylates, and suitable resin models such as silane and polyester acrylate are selected and a reasonable addition amount is determined to prepare high-performance UV glue. The prepared IMR holographic film has good performance in various properties and shows excellent resistance and mechanical properties. From the test results in the above table, it can be seen that the hardness of Comparative Examples 1 and 2 without adding vinyl silane is low, the wear resistance is poor, the adhesion is unqualified, and the high temperature, high humidity and boiling resistance are also unqualified, indicating that vinyl silane has a great effect on improving the hardness, wear resistance and high temperature, high humidity and boiling resistance of UV glue. The hardness, wear resistance and release peeling ability of Comparative Examples 3 and 4 without adding trifunctional active monomers and trifunctional mercapto-modified acrylates are all poor, indicating that trifunctional active monomers and trifunctional mercapto-modified acrylic resins have a certain effect on improving the hardness and wear resistance of UV glue. Comparative Example 5 replaces polyester acrylate with polyether acrylate, and Comparative Example 6 replaces aliphatic polyurethane acrylate with polyether acrylate. Its hardness and wear resistance are slightly inferior to those of Example 3, and its adhesion, high temperature, high humidity and water boiling resistance are basically unqualified, indicating that aliphatic polyurethane acrylate and polyester acrylate are helpful to improve wear resistance and scratch resistance, and are good for improving the high temperature, high humidity and water boiling resistance of the glue system. Replacing with other types of acrylates will have an adverse effect on the overall performance of the glue. After replacing the trifunctional active monomer and trifunctional mercapto-modified acrylate in Comparative Example 3 and Comparative Example 4, its curing speed is significantly slowed down, indicating that the addition of high-functional monomers and acrylates is helpful to improve the curing rate of the glue system.

[0089] The methods for each performance test are as follows:

[0090] Hardness test: According to the "Instrumental Method" specified in GB / T 6739, use a Zhonghua brand high-grade drawing pencil to scratch 20mm at a speed of 0.5mm / s. It is required that there are no scratches or abrasions in the five scratches, and record the maximum pencil hardness that can be tolerated.

[0091] Wear resistance test: A clean spun yarn glove is wrapped with a 500g weight and placed vertically on the sample surface. It is slid back and forth 2000 times in the horizontal direction (one reciprocating motion) at a speed of 20 to 30 times / min and a stroke of 10cm. The sample must not change color or show the bottom after the test.

[0092] Release peeling performance test: The test is conducted according to ASTM D1876 standard, and a vertical force is applied to the surface of the film to peel off the release layer 102. The release layer 102 is required to be completely peeled off and have good peeling performance.

[0093] Adhesion test: According to the cross-cut test specified in GB / T 9286, the sample surface is cut manually with a cutting interval of 2mm on the smooth part of the paint film surface. The coating adhesion is required to be no less than level 0.

[0094] High temperature and high humidity resistance test: Place the film in a high temperature and humidity test box at a temperature of 70℃±2℃ and a humidity of 95±1% for 120 hours, then take it out and observe the appearance. Place it at room temperature for 0.5 hours and then test the adhesion. If there is no abnormality in the appearance of the sample after the test, it is qualified if the adhesion reaches level 0.

[0095] Boiling test: Boil the membrane in 85℃ water for 2 hours and then take it out. Wipe off the residual water on the surface and then conduct appearance inspection and adhesion test. The sample must have no abnormal appearance after the test and the adhesion must reach level 0 to be qualified.

[0096] UV aging test: UVA-340 lamp, blackboard temperature 60°C, irradiance 0.89W / m 2 , take out after 168 hours of testing, cool to room temperature and compare the color difference ΔE before and after the test. The color difference is required to be less than 3.0.

[0097] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A UV glue for holographic IMR film, characterized in that: The raw materials include the following components in parts by weight: 3-10 parts of vinyl silane, 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, 10-20 parts of trifunctional mercapto-modified acrylate, 25-40 parts of difunctional active monomer, 5-10 parts of trifunctional active monomer, and 3-6 parts of photoinitiator.

2. The UV glue for holographic IMR film according to claim 1, characterized in that: The bifunctional reactive monomer includes one or more of dipropylene glycol diacrylate, tripropylene glycol diacrylate and triethylene glycol diacrylate.

3. The UV glue for holographic IMR film according to claim 1, characterized in that: The trifunctional reactive monomer is one of trimethylolpropane triacrylate or pentaerythritol triacrylate.

4. The UV glue for holographic IMR film according to claim 1, characterized in that: The photoinitiator is 1-hydroxycyclohexyl phenyl ketone.

5. The UV glue for holographic IMR film according to claim 1, characterized in that: The vinyl silane is one of vinyl triethoxy silane and vinyl trimethoxy silane.

6. The method for preparing UV glue for holographic IMR film according to any one of claims 1 to 5, characterized in that: Weigh 30-50 parts of active monomer, add 3-6 parts of photoinitiator, stir evenly, then add 15-25 parts of polyester acrylate, 15-25 parts of aliphatic polyurethane acrylate, 10-20 parts of trifunctional mercapto-modified acrylate in sequence, stir until completely dispersed, finally add 3-10 parts of vinyl silane, stir and disperse evenly, and stand in the dark to obtain UV glue; The reactive monomers include bifunctional reactive monomers and trifunctional reactive monomers.

7. A holographic IMR film, characterized in that: The film comprises a base film layer, a release layer, a holographic layer, a plating layer, an ink layer and a glue layer from bottom to top. The holographic layer is made by UV embossing using the UV glue prepared according to claim 6 and has a thickness of 5-15 μm.

8. The holographic IMR film according to claim 7, characterized in that: The base film layer is made of polyethylene terephthalate and has a thickness of 35-50 μm.

9. The holographic IMR film according to claim 7, characterized in that: The release layer is an organic silicon coating, which is peeled off together with the base film layer after injection molding, and the coating is an aluminum coating layer or a transparent medium layer.

10. A method for preparing a holographic IMR film according to any one of claims 7 to 9, characterized in that: UV molding is performed on the base film layer coated with the release layer, and the holographic pattern on the nickel plate is transferred to the surface of the release layer through UV glue. After that, the plating layer, ink layer and glue layer are coated in sequence to obtain the IMR holographic film.

Images